


Crescendo

by Ignis_Sassentia



Series: Song of the Soul (A Musical Soulmate AU) [2]
Category: Final Fantasy XV
Genre: But it's me so there will probably be some sort of angst in the middle somewhere, Cellist Lunafreya, F/M, M/M, Pianist Ignis, Platonic Soulmates, Romantic Soulmates, Soulmate AU, Tenebraean Ignis, This should be ridiculously fluffy, musical soulmates
Language: English
Status: In-Progress
Published: 2018-01-08
Updated: 2018-08-25
Packaged: 2019-03-02 08:25:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,603
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13314303
Author URL: https://archiveofourown.org/users/Ignis_Sassentia/pseuds/Ignis_Sassentia
Summary: Ignis and Lunafreya have known they were platonic soulmates since they were children. What neither of them realized, however, is that they both also have a romantic soulmate--and it's the same person.Noctis has never told anyone that he has a soulmate, let alone two. He's more or less resigned himself to focusing on his duties as Crown Prince instead. All that changes when he realizes both of his soulmates are already intimately involved in his life.A soulmate AU where romantic soulmates share the same unique melody in their heads, and platonic soulmates have a unique melody/harmony pair. Intertwines withTuneless, especially for the first few chapters.





	1. Chapter 1

The train was late.

Ignis checked the time on the clock on the side of the station again as he stood on the platform, bundled up in his winter coat and scarf, a steaming coffee in either hand. Though if the train was much later, the coffee would be cold by the time Lunafreya arrived.

Why she had insisted on moving to Insomnia in the middle of winter, Ignis would never understand. But he knew better than to argue with her once she’d set her mind to something. That was always a losing battle. Had been since they were children.

He sighed and shifted his weight to peer down the tracks. At least he could see the train now, though it would still probably take a good ten minutes to pull into the station and start allowing passengers to disembark. How frustrating. He had work he could be doing.

Stacking one coffee cup on top of the other to hold them in one hand, he pulled out his phone and scrolled quickly through his emails. At least he hadn’t missed anything terribly important: a few updates about the renovations on the west wing of the Citadel, a couple of meeting requests, three emails from Noctis about new arcades he wanted to try instead of attending his studies, and entirely too much spam. He deleted the unwanted messages and replied to Noct’s emails with a stern reminder to finish the first volume of _The Abridged Lucian History_ by their next tutoring session in two days.

By the time he was finished with that, the train had finally pulled into the station and sat hissing and clicking on the rails. He tucked his phone back into his pocket, remedied the precarious coffee cup stack, and began to scan the people stepping onto the platform for the familiar blonde.

“Ignis!” Lunafreya’s voice carried over the chatter of the crowd.

He turned and instantly smiled as he caught sight of her fighting her way toward him in her pristine silver coat and delicate blue-and-white scarf, carrying that familiar lavender cello case. Careful not to spill their coffee, he pushed his way toward her.

When they reached each other, Luna set down her cello and the two other bags she carried, then pulled him into a tight hug. She pulled back only to kiss both of his cheeks and allow him to do the same.

It felt as if a piece of Ignis’ soul had snapped back into place for the first time in almost four years. Four years without being able to visit his platonic soulmate at home in Tenebrae, thanks to both of their growing responsibilities and completely packed schedules, had been far more painful than he’d anticipated. Of course, he should have expected it, since they’d realized their bond after he’d moved to Insomnia to look after the Crown Prince--but his yearly visits home had vanished under the weight of his increased responsibilities. It had helped to have a recording of their Soul Songs to listen to her melody on particularly bad days, and their bi-weekly phone calls had been a blessing, but those were nothing in comparison to her presence.

“How was the trip?” Ignis asked as he took a half-step back, the coffee miraculously still unspilled. He offered her one of the cups with a broad smile. “Did you get any rest on the train?”

Luna shook her head and took a grateful gulp of the coffee. “You know I can’t sleep on trains, Iggy. And you know you didn’t need to come get me. You look awful. Aren’t they letting you rest at all?”

“I’m afraid not.” Ignis chuckled and leaned down to grab two of Luna’s bags with his free hand, leaving her to carry her precious instrument. Sipping his own coffee, he began to lead her through the crowd toward where he’d parked the borrowed car. “Between keeping up with His Highness, my own studies, Council meetings, planning for the Solstice celebrations, and making contingencies in case Niflheim breaks the ceasefire--you’ve heard their latest movements, haven’t you?”

Luna made a soft hum of agreement and nodded for him to continue.

“Well, suffice it to say I haven’t had the luxury of downtime in quite a while.” Ignis chuckled weakly as he dodged around a particularly stuffed luggage cart.

Luna’s unimpressed look was practically palpable. “Ignis. Seriously. They’re going to work you to death if you don’t put your foot down. Even I insist on taking a break now and then.”

“Yes, well, you have certain advantages as the future Oracle,” Ignis pointed out gently. It had been a long-standing tension between them--Lunafreya always refused to recognize that the world didn’t see her as equal to someone like Ignis. She was to be the Oracle when Aunt Sylva passed, and Luna had already started to exhibit some of the Oracle’s power. But she still ignored the particular luxuries that came with her position--like the ability to insist on taking a rest. “I’m afraid my position doesn’t exactly afford me the same flexibility.”

Luna huffed and knocked her shoulder against his. “It isn’t about ‘my position,’ Iggy. You haven’t asked, have you?”

“It’s quite all right, darling,” Ignis assured as they finally came even with the car he’d borrowed from His Majesty’s fleet for the day. He set Luna’s bags down to fish the keys out of his coat pocket. “I imagine things ought to calm down after the Solstice. And His Majesty has already organized three days’ leave for most of the Citadel staff during the celebrations. I can manage until then.”

Luna’s lips pursed into a thin, unimpressed line. The silent, unmistakable sign that she was very much _not_ pleased. Sure enough, the next word out of her mouth held that quiet exasperation that only the people close to her recognized. “ _Ignis._ ”

Ignis wasn’t entirely certain who had drawn that tone from Luna the most--himself or Ravus--but he’d become rather immune to it over the course of growing up with her. He popped the trunk on the car and carefully loaded her luggage in, somehow managing not to spill his coffee as he did so. “I know my limits. I’m not just pushing myself for the sake of seeing how far I’ll go.”

“I’m going to speak with Noctis about this,” Luna proclaimed firmly. She carefully settled her cello case beside her bags and snapped the trunk shut. “If you won’t listen to me, perhaps you’ll listen to him.”

“‘Not about your position’ indeed.” Ignis quirked a brow at her and took a sip of his coffee. Then, before she could spit out the undoubtedly long-winded refutation to that, he stepped around her to open the passenger side door. “Let’s get out of the cold, shall we?”

She graced him with another little press of her lips, but slid into the seat without a word.

Ignis closed the door once she was settled, then rounded the car to climb into the driver’s seat. He started the car and blasted the heater as he pulled out of the parking spot and joined the line of vehicles heading away from the station. The engine purred pleasantly on the drive and Ignis took the opportunity to point out some of the more interesting aspects of the Insomnian skyline as a distraction from their previous conversation. He could tell Luna wasn’t about to let him off the hook that easily, but it was worth the attempt.

Somehow, they made it to the high rise apartment building just on the edge of the Citadel District without returning to the topic of Ignis’ work habits. A fact for which he was eternally grateful.

They carried Luna’s luggage to the elevator and Ignis pointed out the features of the building that had attracted him in the first place: the dedicated doorman, the workout suite and pool, the locked mail room, and the state-of-the-art business center. He didn’t mention, however, the incredible security systems he’d personally insisted they install throughout the shared spaces when Luna had expressed interest in moving to Insomnia with him. One could never take too many precautions with the safety of the future Oracle, even with the tentative peace with Niflheim.

Ignis’ apartment was on the twenty-second floor, in the corner furthest from the elevators. The view wasn’t incredible, due the building’s location practically in the heart of the city, but the spacious two-bedroom had served him well since he’d moved out of his uncle’s flat and into his own just after his last visit to Tenebrae. He’d been a bit hesitant to transform his spare room from an office into a bedroom for Luna, but he had made the sacrifice to have her near.

He set her bags in her room and retreated to the kitchen to make lunch as she began to unpack. By the time he’d finished the simple grilled cheese sandwiches and tomato soup--one of Luna’s favorite meals from their childhoods--Luna had shed her coat and scarf and settled on the low couch near the windows with her phone.

“When will Umbra and Pryna be joining us?” Ignis asked quietly as he slid their plates onto the coffee table, careful not to spill the steaming soup.

Luna flipped her phone screen off, shifted to grab her plate, and scooted a little closer to him. “Within the week, I’d imagine. Gentiana will bring them over once I’ve settled in.”

Ignis hummed quietly in agreement and glanced around the living room, mentally taking stock of the things he’d need to tidy up or rearrange before the dogs’ arrival. They might have been messengers of the gods and incredibly intelligent, but they were still dogs, after all. And the last thing he needed was for Umbra to take to chewing on his official reports from the Citadel, or Pryna getting a little too curious about the delicate figurines Noctis had gotten him for holidays and birthdays over the last few years.

“You know,” Luna said into the silence as they finished eating, “I imagined you would have a piano of some sort. A beat-up old upright or something. There’s room enough here.”

Ignis wasn’t entirely certain _how_ he managed to avoid choking on his last bite of grilled cheese sandwich, but he managed to swallow it uneventfully somehow. “It simply never became a priority, I’m afraid. I don’t tend to spend all that much time at home, so it seemed rather...frivolous to seek one out.”

“It isn’t frivolous to do things that make you happy,” Luna reprimanded gently, resting a hand on his knee for a moment.

Ignis opened his mouth to protest, but his phone buzzed before he could speak. He sighed and leaned forward to set his plate back on the coffee table as he fished the phone out of his pocket.

“Specs,” Noctis’ voice said as soon as Ignis picked up, even before he’d had a chance to say hello. “Have you picked up Luna yet?”

Ignis’ shoulders tightened automatically at the tight, anxious tone in his prince’s voice. He was moving without thinking, surging off the couch and striding toward the counter where he kept his work bag. “What’s wrong, Highness?”

“Nothing’s _wrong_ ,” Noct replied carefully, which only raised Ignis’ hackles further. The prince cleared his throat and Ignis swore he heard Prompto’s voice in the background, though he couldn’t make out coherent words. “Look, just...can you come over? And bring Luna?”

Ignis paused with his work bag slung over his shoulder. He glanced back at his soulmate and frowned thoughtfully. “Whatever for, Noct? You’ll see her soon enough. Don’t you think we ought to let her rest a bit?”

“It’s all right,” Lunafreya said quietly as she scooped up the lunch plates and padded toward the kitchen. “I don’t mind.”

Ignis gave her an exasperated look as Noctis stammered out some half-hearted excuse about greeting the future Oracle properly as the Crown Prince.

Luna chuckled and blew him a teasing kiss over the kitchen counter.

Ignis rolled his eyes and adjusted his glasses with his free hand. “Very well, Highness. We’ll be there in ten minutes or so.”

“Thanks,” Noctis breathed, a hint of a smile in his voice. “See you soon.”

“Indeed.” Ignis waited for Noct to hang up out of habit and sighed as he slipped the phone back into his pocket. He turned to Luna, who had already started washing dishes. “His Highness requests our presence as soon as possible. Apparently, he’s quite eager to see you.”

Luna chuckled as she rinsed out one of the soup bowls. “It has been a while.”

“Almost ten years, I believe.” Ignis sighed as he adjusted the strap of his bag on his shoulder, remembering that visit to Tenebrae for one last check-up after his injury. Before all of them started to get too entangled in their various duties.

Luna hummed softly in agreement. “We’ve spoken a few times since, but I’m looking forward to seeing how he’s grown for myself.”

“He’ll make quite a fine king some day.” Ignis smiled softly and pushed his glasses up on his nose.

“Is that a crush I hear?” Luna asked over the rush of the water in the sink, a teasing smile curving her lips.

Ignis choked on nothing and covered his mouth with his hand. “Luna! I...would never.”

She laughed, set the dishes in the drying rack, and turned off the water. Smirking to herself, she dried her hands on the dish towel. “You’re entirely too proper for something so ghastly as being attracted to someone you’re close to.”

“Certainly not my prince,” Ignis agreed firmly, though he knew it was a fool’s errand to lie to his cousin. She had always been able to read him like a children’s book, even without any special Oracle powers.

“Of course not.” She chuckled again and glanced up, head tilted ever so slightly to the side. After a moment, she asked, “Do you know if he has a soulmate?”

Ignis frowned and that and considered the question a moment. Finally, he shook his head. “I suppose it’s possible, but he’s never made mention of a Song.”

Luna hummed thoughtfully and propped her hands on her hips. “Hm. Well, shall we go see what His Highness has in store for us?”

Ignis gave her his best impression of her unimpressed pursed lips, which only sent her off into giggles once more, and reluctantly ushered her toward the door.


	2. Chapter 2

Ignis hesitated a moment outside Noct’s apartment door, listening intently to the muffled conversation filtering from inside. Lovely. Noct, Gladio, _and_ Prompto. As if only one of them wouldn’t be overwhelming enough for Lunafreya, who had just finished a three-day voyage.

Luna chuckled softly and touched his elbow. “Ignis. It’s just a little party. Stop fretting and open the door.”

He soundly resisted the urge to pull a face and adjusted his glasses instead. He was being foolish, of course. These were his friends, and Noctis and Lunafreya had a rather intimate friendship despite their long separation. Waiting outside in the hall like a coward wasn’t helping any of them.

With a resigned sigh, he knocked on the door. Noct had obviously wanted this to be a surprise for Luna--might as well play along as well as he could.

The sounds from inside the apartment instantly went silent. Footsteps thumped on the hardwood floor, the lock clicked, and the door swung open to reveal Noctis, very clearly attempting to look more confident and suave than he felt.

That familiar half-sheepish, half-cocky smile simultaneously made Ignis’ gut twist with attraction and relaxed the tension in his shoulders. As much as he hated to admit it, Luna had been right. He did have a crush on Noctis. A massive one. He just didn’t dare act on it. It wasn’t his place.

“Hey, Specs,” Noct said, though his dark eyes flicked over Ignis’ shoulder to Luna. His smile wavered a little, but remained more or less in place. “Luna…”

Luna’s smile was brilliant as she ducked her head respectfully. “Prince Noctis. It’s wonderful to see you again.”

“Yeah.” For a moment, the prince looked completely lost--the same bewildered expression Ignis had seen so many times during a council meeting when King Regis unexpectedly called on Noctis for input. “Uh.”

Ignis opened his mouth to suggest allowing them into the apartment, but closed it again when Gladio yanked the door open further.

Gladio smiled and bowed, managing to elbow Noctis subtly with the motion. “Lady Lunafreya. It’s an honor to meet you. I’m Gladiolus Amicitia, Noct’s Shield. But everyone calls me Gladio. Come on in. Unless His Highness would rather party in the hall.”

Noct made a strange little strangled noise and scrambled backward.

“After you,” Ignis muttered, turning to motion Luna into the apartment while hiding his amused smile from his prince.

Luna made no such effort to conceal her delight. She grinned widely as she slipped past Gladio with a soft but regal greeting.

“Please tell me you attempted to reign him in a little,” Ignis whispered, removing his shoes in the entryway beside his friend. He set his bag down and glanced up at Gladio just in time to catch those golden eyes roll in exasperation.

“Of course I did. But when does he ever listen to us?” Gladio chuckled softly, a deep rumble in his chest, and shrugged. “Managed to cut a deal, though. He got his way on the decorations if he called off the catering crew.”

Ignis blinked up at the taller man. He let out a small huff of a laugh. “A catering crew?”

“Yep. Royal party planning training took hold after all.” Gladio chuckled again and motioned toward the living room with his chin. “Let’s go, before Prompto talks her ear off.”

Ignis nodded and stepped into the apartment proper.

The decorations were indeed a special brand of _Noctis_ \--streamers strung along the ceiling in a riot of color, moogle and chocobo designs stuck to the wall, a fish-shaped pinata in one corner, and a spinning multi-colored lamp on the coffee table. And, yet, somehow, it _worked_. Ignis would never understand how the prince’s rather eclectic ideas managed to come together when everything on Eos said they shouldn’t.

Noctis had already pulled Luna over to the bank of floor-to-ceiling windows. He and Prompto were babbling anxiously, pointing out various sights--some Ignis had already covered and some more vague ones, like their favorite arcade, which was only barely visible several blocks away.

As Ignis approached, the prince turned and gave him one of his patented “help me” looks.

“Quite the welcome, Highness,” Ignis said easily, just loud enough to be heard over Prompto’s rather harried description of some park across the city where he apparently liked to take photographs on occasion. “Perhaps we ought to consider making ourselves comfortable? Gladio, would you be so kind as to sort out refreshments?”

Gladio tossed him a mocking salute, winked at Noct, and slipped into the kitchen. He leaned against the counter and pulled his cell phone out of his pocket, scrolling and tapping without a word.

Bolstered by Ignis taking charge of the situation, Noctis cleared his throat and motioned to the couch closest to the windows. “Um. Make yourself comfortable, I guess. Sorry for kind of jumping on you like that, I just--”

“I understand,” Luna said with a gracious smile. She elegantly shrugged out of her jacket and scarf and draped them over the back of the couch before settling on the edge of one cushion. “It is quite overwhelming to see each other again after so long. And to finally meet the man who helped Pryna all those year ago.”

Prompto went bright red in an instant, the blush accenting the smattering of freckles across his cheeks.

Ignis bit the inside of his cheek to avoid snickering in a most unbecoming way as he lowered himself into one of the armchairs opposite the couch, leaving the space beside Luna for Noctis.

“Wait, what?” The prince glanced between Luna and Prompto in confusion.

“Oh, it was nothing!” Prompto proclaimed, a little too quickly and a little too loudly. He laughed uncomfortably. “I’m always helping animals, you know? Just ask Noct. He’ll tell you. It’s a little bit crazy, but I can’t help it. Someone’s gotta help ‘em. Might as well be me, right?”

“Indeed.” Luna gave him a gracious smile and changed the subject with all the elegance expected of the future Oracle.

After that, the conversation went smoothly for quite some time. Gladio rejoined the rest of them, perched awkwardly on an ottoman, and seamlessly joined a discussion of the upcoming Solstice celebrations. Not long after, a delivery man arrived with several boxes of food, and Ignis silently applauded Gladio’s choices--a well-balanced mix of Insomnian sweets with savory Tenebraean delicacies, and a six-pack of Noctis and Prompto’s favorite soda to keep the boys happy.

It was in the middle of a spirited conversation about which were better—chocobos or moogles—that Luna’s cell phone rang.

Ignis instantly recognized the ringtone as a few bars of one of their Soul Songs. Lunafreya’s melody, as a matter of fact, that he’d played on the piano once she’d taught it to him. He smiled despite himself and hummed the harmony under his breath as she excused herself and took the call. It wasn’t until he noticed Noctis staring at him slack-jawed that he realized what he’d done.

He cleared his throat and adjusted his glasses, muttering an apology.

“That…” Noctis licked his lips, scrubbed at his face, then blurted, “That was my Soul Song.”

The air in the room pulled taut in an instant.

Ignis couldn’t help a glance in Gladio’s direction. The pure shock on the Shield’s face verified Ignis’ suspicions--Noct had never mentioned having a Song to Gladio, either.

“I thought you didn’t have a Song, dude,” Prompto said into the tense silence, voice just as cheerful as ever, though his shoulders had curled inward just a little.

Noctis winced and ran his fingers through his hair as he shot his friend an apologetic glance. “I dunno, man, it just...never seemed important.”

Prompto fidgeted in his seat, not quite making eye contact. “Yeah. Right.”

“You’re certain your Song matches Lady Lunafreya’s?” Ignis asked cautiously, partially to gather information and partially to save the poor blond from any further discomfort as best he could.  

“Yeah.” Noct sucked in a deep breath and let it out slowly before admitting, “Well...one of them.”

“What’s that supposed to mean?” Gladio leaned forward on the ottoman, bracing his elbows on his knees, and scowled at the prince. “And why the hell didn’t you tell your Shield about it earlier?”

Noctis shrugged uncomfortably. “It’s not like I really get a say in who I marry or anything anyway.”

Gladio’s scowl deepened and he growled, “ _Noct_.”

“It’s rather a...complicated situation, Gladio,” Ignis said softly before the argument could continue. He adjusted his glasses and fixed his gaze on the wall behind Gladio, just over his friend’s shoulder, as his mind whirled through all the questions he needed answered. Finally, he settled on one and glanced back at Noctis. “How many Songs do you have, Highness?”

Noct squirmed a little again before admitting in the quietest of whispers, “two.”

Ignis’ heart beat faster in his chest, but he had enough formal training to keep his face completely blank. If Noctis had two Soul Songs and one of them matched Luna’s, what were the odds his second matched Ignis’? And what in the world would they do should that be the case? It was easier with Luna--the prince and the Oracle would make a lovely, politically-sound match. But a prince and his advisor? That was a different story entirely.

“Are they both melodies?” Gladio asked roughly, his hands in fists in his lap.

Noctis nodded without looking up.

“Hey, uh...I’ll be right back,” Prompto muttered into the silence before jumping out of his chair and stumbling for the door.

Without thinking, Ignis fumbled for his phone. He had full recordings of both his and Luna’s Songs. They’d played them together on piano and cello over his last few visits home to Tenebrae. The odds that Noctis was soulmates with the both of them were slim, but he had to at least try.

Of course, Luna returned before he could pull up the files. She glanced between the three remaining young men with the barest hint of a concerned frown. “Is everything all right?”

Gladio--never quite able to control himself when he got caught off-guard over something in relation to Noct’s safety--snarled quietly and shoved himself up off the ottoman. “Why don’t you ask His Highness?”

Ignis lowered his phone into his lap and watched helplessly as his eldest friend stormed off, leaving him alone with his platonic soulmate and the man he’d been hopelessly in love with for quite some time. What a dubious situation.

“Noctis?” Luna asked gently. She took her seat once more, the perfect picture of a lifetime of training in composure.

The prince, on the other hand, looked as if he wished he could sink into the couch cushions and disappear.

“It appears,” Ignis said after an awkward moment, “that we were mistaken about the nature of our Soul Songs.”

Her piercing gaze swung to him and she tilted her head slightly to one side. “How so?”

“His Highness seems to share your melody.” The pure lack of emotion in Ignis’ voice would have made him cringe at any other point. But he was too far into his mild panic to register it as a potential problem.

She looked back to Noct, one delicate eyebrow lifted.

“I recognized your ringtone,” Noctis muttered to the floor, anxiously rubbing the back of his neck.

“I see.” She chewed on her lip for a moment before shifting and glancing at Ignis.

Ignis was more than capable of reading the question in her eyes. He sucked in a breath, shook his head incrementally, and muttered, “I’m uncertain about my own.”

Noct’s head snapped up and he frowned at his advisor. “Specs…”

Ignis smiled--the same, polite smile he had perfected for court and politics--and adjusted his glasses. “Since you’ve already admitted to having two Songs, Highness, would you be amenable to...finding out?”

“Two songs?” Luna asked quietly.

“Yeah,” Noctis whispered. He gave her a self-conscious smile before turning back to Ignis. “Yeah, uh...go for it.”

Ignis nodded and looked back down to his phone. His thumb shook as he swiped to bring up the files. As soon as the music started to play, he closed his eyes. He wasn’t certain he could handle watching Noctis’ reaction.

Cello and piano filled the apartment, slightly tinny from the phone’s speakers. The perfect harmony thrummed in Ignis’ blood, the very pulse of his heartbeat. It was more familiar to him than breathing.

And then, suddenly, it wasn’t.

Noctis’ soft humming in perfect time with the melody, only slightly off-key, somehow skewed the song into something utterly unfamiliar.

In all his wildest dreams, Ignis had never actually imagined he would have a romantic soulmate--let alone that it would be the Crown Prince of Lucis, or that Lunafreya would have the same connection.

For the first time in quite a while, Ignis Scientia--advisor to the prince, platonic soulmate of the Oracle, political chess piece between Lucis and Tenebrae--had absolutely no idea how to handle a situation.


End file.
